1 files changed, 28 insertions, 10 deletions

diff --git a/ot_http.c b/ot_http.c
index bb6ff24..602ff94 100644
--- a/ot_http.c
+++ b/ot_http.c
@@ -39,22 +39,30 @@ ssize_t      g_stats_path_len;
 
 enum { SUCCESS_HTTP_HEADER_LENGTH = 80, SUCCESS_HTTP_SIZE_OFF = 17 };
 
-int http_adopt(const int64_t sock, struct http_data *cookie) {
-  struct http_data *heap = malloc(sizeof(*heap));
+struct http_data *http_adopt(const int64_t sock) {
+  struct http_data *cookie = fdstate_cookie(sock), *heap;
+  int               interest;
 
-  if (!heap)
-    return -1;
+  if (!cookie || !(cookie->flag & STRUCT_HTTP_FLAG_ONSTACK))
+    return cookie;
+
+  if (!(heap = malloc(sizeof(*heap))))
+    return NULL;
 
   *heap = *cookie;
   heap->flag &= ~STRUCT_HTTP_FLAG_ONSTACK;
+
+  /* Publishing the cookie is what lets another thread reach this connection,
+     so nothing may touch it afterwards, not even to read what it asked for */
+  interest = heap->interest;
   fdstate_set_cookie((int)sock, heap);
 
-  if (event_add((int)sock, heap->interest, fdstate_generation((int)sock)) == -1) {
+  if (event_add((int)sock, interest, fdstate_generation((int)sock)) == -1) {
     fdstate_set_cookie((int)sock, cookie);
     free(heap);
-    return -1;
+    return NULL;
   }
-  return 0;
+  return heap;
 }
 
 /* Give up a connection: the one place that knows everything hanging off it. */
@@ -348,13 +356,17 @@ static ssize_t http_handle_stats(const int64_t sock, struct ot_workstruct *ws, c
     }
 #endif
 #endif
-    /* Pass this task to the worker thread */
     cookie->flag |= STRUCT_HTTP_FLAG_WAITINGFORTASK | STRUCT_HTTP_FLAG_CHUNKED;
 
     /* Clients waiting for us should not easily timeout */
     fdstate_set_expiry(sock, 0);
-    fullscrape_deliver(sock, format);
     http_interest_set(sock, cookie, 0);
+
+    /* Everything this connection needs has been written, so it can be given
+       a home of its own and only then be made reachable by a worker thread */
+    if (!http_adopt(sock))
+      HTTPERROR_500;
+    fullscrape_deliver(sock, format);
     return ws->reply_size = -2;
   }
 #endif
@@ -366,6 +378,9 @@ static ssize_t http_handle_stats(const int64_t sock, struct ot_workstruct *ws, c
 
     /* Complex stats also include expensive memory debugging tools */
     fdstate_set_expiry(sock, 0);
+
+    if (!http_adopt(sock))
+      HTTPERROR_500;
     stats_deliver(sock, mode);
     return ws->reply_size = -2;
   }
@@ -448,8 +463,11 @@ static ssize_t http_handle_fullscrape(const int64_t sock, struct ot_workstruct *
   cookie->flag |= STRUCT_HTTP_FLAG_WAITINGFORTASK | STRUCT_HTTP_FLAG_CHUNKED;
   /* Clients waiting for us should not easily timeout */
   fdstate_set_expiry(sock, 0);
-  fullscrape_deliver(sock, format);
   http_interest_set(sock, cookie, 0);
+
+  if (!http_adopt(sock))
+    HTTPERROR_500;
+  fullscrape_deliver(sock, format);
   return ws->reply_size = -2;
 }
 #endif